Cooling arrangement for a copying machine

ABSTRACT

A THERMO COPIER HAS A TRANSPARENT TUBULAR ROLLER COPERATING WITH A COUNTERPRESSURE ROLLER. A SOURCE OF INFRARED RADIATION IN THE INTERIOR OF THE TRANSPARENT ROLLER HEATS SHEETS PASSING BETWEEN THE ROLLERS, AND ALSO THE ROLLERS. A BLOWER DISCHARGES AN AIRSTREAM AGAINST THE COUNTERPRESSURE ROLLER BY WHICH THE AIRSTREAM IS DIVIDED INTO TWO COOLING AIRSTREAMS FLOWING TRANSVERSELY TO THE AXES OF THE ROLLERS ABOVE AND BELOW THE SAME AND BEING DISCHARGED THROUGH SEPARATE OUTLET OPENING.

Feb. 9, 1971 G. RITZERFELD 3,561,368

COOLING ARRANGEMENT FOR A COPYING MACHINE Filed April 1, 1968 &

lnventor: Gerhard RI fZeJpe/d mnzmz 5. \VM

United States Patent O 3,561,868 COOLING ARRANGEMENT FOR A COPYING MACHINE Gerhard Ritzerfeld, Schorlemer Allee 14, Berlin 33, Germany Filed Apr. 1, 1968, Ser. No. 717,744 Claims priority, application7Germany, Apr. 7, 1967, R 03 Int. Cl. oosb 27/10 US. Cl. 355-110 11 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Copying machines are known in which a thermo sensitive copy sheet and an original are transported by a pair of transporting and copying rollers including a transparent roller and a counterpressure roller. A source of infrared radiation is located in the transparent roller and causes exposure of the copysheet. Since a great amount of heat develops within the housing of the machine, copying machines of this type are provided with a blower located in the rear part of the housing.

In accordance with the prior art, the housing is closed, except for an inlet and an outlet for the sheets.

The arrangements according to the prior art do not obtain a uniform cooling of the copying and transporting rollers, and particularly at the center of the hollow transparent roller and of the counterpressure roller, very high temperatures develop which cause a higher exposure temperature after prolonged use of the machine than at the beginning, resulting in improperly exposed portions at the center of the copy sheet.

SUMMARY OF THE INVENTION It is one object of the invention to overcome this disadvantage of known copying machines, and to cool the copying rollers by air streams guided across the same.

Another object of the invention is to provide a copying machine in which cooling air streams flow from the rear part of the housing past the copying rollers and out of suitable openings in the front part of the housing.

Another object of the invention is to prevent the overheating of parts of the copying rollers of a copying machine employing a source of infrared radiation.

Another object of the invention is to cool a thermo copier in such a manner that the produced copies are of a uniform appearance irrespective of the time during which the copier was in continuous use.

With these objects in view, the present invention relates to a cooling arrangement for a copying machine, particularly for a thermo copier employing a source of infrared radiation.

One embodiment of the invention comprises copying and transporting roller means mounted in a housing to receive and transport sheets inserted through an inlet in the front part of the housing by an operator, and including a transparent roller enveloping a heat-producing source of radiation, and a counterpressure roller. Blower means are located in the rear part of the housing and discharge air 3,561,868 Patented Feb. 9, 1971 forwardly toward and past the roller means transversely to the axes of the same into the front housing part and out of air outlet openings in the same.

The streams of air are divided by the roller means and flow forwardly above and below the rollers and cool the same.

The front part of the housing, and more particularly the front wall, has air outlet openings located at the level of the transparent roller for the passage of air flowing above the same. The bottom portion of the front part has an air outlet for streams of air flowing below the transparent roller and the counter-pressure roller.

Since the cooling air streams are discharged at the front of the housing, where the operator is positioned and supplies the sheets to the machine, the air flows freely along the top and bottom parts of the copying rollers, and particularly of the transparent roller which may consist of glass, so that any overheating in the region of the transparent roller, and particularly at the middle portion of the same is prevented.

In the preferred embodiment of the invention, the air outlet openings in the front wall of the housing are horizontal slots formed between downwardly and forwardly slanted wall portions constructed similar to a Venetian blind. The slanted blind portions block radiation from the source of radiation so that an operator standing in front of the machine is not exposed to the radiation, and does not see the source of radiation. It is also possible to slant the wall portion upward and forward in a position blocking radiation. The slots or other air outlet openings are advantageously covered by a wire mesh or net which permits the passage of air, but partly blocks radiation emitted by the source of radiation.

It is advantageous to mount the front part of the housing on the rear part for pivotal movement between a closed position and an open servicing position.

In the preferred embodiment of the invention, guide means for the inserted sheets are provided, and air outlet openings are disposed in the front part of the housing above and below the guide means so that air streams flow above and below the same, and also above and below the copying rollers.

The novel features which are considered as characteristic for the invention as set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of a specific embodiment when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The single figure of the drawing is a fragmentary schematic vertical sectional view illustrating an embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT A pair of vertical side walls 6, of which only one is shown in the drawing, is mounted on a trough-shaped base portion '5 of a housing whose upper rear portion 17 rests on the base portion 5. The rear housing portion 17 is connected by pivot means 17a with a front part 19 which can be turned between the illustrated normal position and a higher open position permitting access to the interior of the housing during servicing of the machine. Housing portion 17 has a rear wall formed with a large air inlet opening, and front part 19 includes a front wall 19a which has downwardly and forwardly slanted wall portions 20 arranged in the manner of Venetian blinds and forming between each other horizontal slots 21 which serve as air outlet openings. The front part of the base portion 5' has also at least one air outlet opening 22, and preferably a plurality of air outlet slots.

A drive shaft 1a is mounted in the lateral Walls 6 and carries a drive roller 1 which is in frictional contact with the outer surface of a cylindrical transparent roller 2 which freely rests on a supporting roller 4 and a counterpressure roller 3 whose shafts are mounted in side walls 6. The transparent roller 2 does not have journals, but is supported for rotation and held in its proper position by rollers 1, 3 and 4. A source of infrared radiation 8 is mounted within the transparent roller 2 and provided with a reflector 7 which projects the radiation toward the printing line formed at the bight of rollers 3 and 2. Reflector 7 and infrared lamp 8 may form a unit supported on side 'walls 6.

Front wall 19a is spaced from the base portion and forms an inlet 23 for an original or master superimposed on a copy sheet which are inserted byan operator through inlet 23 into a guide channel 9 formed between a higher guide Wall 13 secured to walls 6, and a lower guide wall 14 which rests on the forward edges of the base housing portion 5. The inner ends of guide walls 13 and 14 are spaced from the transporting and copying rollers 2 and 3 and positioned so that guide channel 9 ends in the region of the bight of rollers 2 and 3.

Sheets supplied to inlet 23 into the guide channel 9 are gripped by the cooperating rollers 2 and 3 and transported into a guide channel 9a between an upper guide Wall 15 and a lower guide wall 16. Guide wall 16- is secured by a lateral bracket to guide wall 15 which is secured to walls 6.

A blower is mounted on bracket 12 on the base portion 5 of the housing, and has a discharge means which blows air transversely to the axes of rollers 2 and 3 in forward direction toward the front part 31 of the housing. A motor 11 mounted on base part 5 drives the shaft of blower 10.

During operation, air is sucked by blower 10 into the rear part 30 of the housing through the air inlet 18, which preferably consists of parallel vertical slots, and blown against counterpressure roller 3 which divides the air stream S into an upper air stream 8,, and a lower air stream S while being cooled. Air stream 5, passes through the gap between guide means 15, 16 and rollers 2, 3 toward the top walls of housing portion 17 and of front part 19, and is deflected downward to pass through the slots 21 in front wall 19a while cooling the front surface of transparent roller 2, and also rollers 1 and 4.

The lower air stream S flows under the guide wall 14 and out of the outlet slots 22 at the front end of base portion 5. A component of the lower air stream S flows between the ends of guide walls 13, 14 and rollers 3 and 2 into the front part of the housing above guide wall 13 and out of the lower openings 21.

Due to the fact that the copying and transporting rollers 2, 3 are cooled on top and on the bottom along the entire length thereof by transverse upper and lower air streams, overheating of the rollers is reliably prevented.

Guide Walls 13 and 14, and guide walls and 16, and more particularly the wall portions thereof located adjacent the rollers 2 and 3, are preferably provided with slots or cutouts to permit parts of air streams S and S to flow through the guide means when no sheets are located in the guide channels 9 or 9a.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of copying machines differing from the types described above.

While the invention has been illustrated and described as embodied in a cooling arrangement for a copying machine in which cooling air streams produced by a blower are discharged through outlet openings in the front wall of the machine housing, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivv alence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. Cooling arrangement for a copying machine, comprising, in combination, housing means having an inlet for sheets and an outlet for sheets, a front part having air outlet means, and a rear part having air inlet means; copying and transporting means mounted in said housing means between said inlet for sheets and said outlet for sheets in a position for transporting sheets inserted through said inlet for sheets along a path to said outlet for sheets, said copying and transporting means including a transparent tubular roller having an axis transverse to said path, means for rotating said transparent tubular roller about said axis, and a counterpressure roller having an axis parallel to said axis, and cooperating with said transparent tubular roller for transporting sheets along said path, said counterpressure roller being located rearwardly of said transparent roller; a heat generating source of radiation mounted on said housing means and located in said transparent tubular roller; and blower means located in said rear part of said housing means in the proximity of said air inlet means rearward of said counter pressure roller and transparent roller, and having an air discharge means projecting forwardly and transversely to said axis of said transparent roller for blowing air transversely to said transparent roller and to said counterpressure roller toward said copying and transporting means so that the blown air impinges said counterpressure roller and is divided by the same into an upper cooling air stream flowing above said copying and transporting means across the upper portion of said transparent roller and of said counterpressure roller, and a lower cooling air stream flowing under said copying and transporting means across the lower portion of said counterpressure roller into said front portion of said housing means and out of said air outlet means whereby said copying and transporting means are cooled by a plurality of high velocity air streams.

2. Cooling arrangement as claimed in claim 1 wherein said housing means include first guide means forming said inlet for said sheets and having a first end portion located in front of the bight between said transparent roller and counterpressure roller for supplying sheets to the same, and second guide means having a second end portion rearward of said bight and said outlet for sheets; wherein said air outlet means in said front part include high and low first air outlet openings located above said first guide means for the passage of two airstreams flowing between said rollers and said first and second end portions, respectively, and at least one air outlet opening located below said first guide means so that said upper airstream flows through said high first outlet openings and parts of said lower airstream flow above and below said first guide means, respectively.

3. Cooling arrangement as claimed in claim 1 wherein said source generates infrared radiation.

4. Cooling arrangement as claimed in claim 1 comprising a reflector in said transparent tubular roller for projecting radiation toward said counterpressure roller.

5. Cooling arrangement as claimed in claim 1 comprising pivot means for mounting said front part of said housing means for movement between a normal closed position and an open servicing position; wherein said air outlet means include a front wall of said front part having at least one outlet opening in the upper portion thereof and at least one outlet opening in the lower portion thereof for at least partly discharging said upper and lower airstreams, respectively.

6. Cooling arrangement as claimed in claim wherein said front wall has slanted wall portions forming between each other a plurality of said outlet openings for air, said slanted wall portions being disposed for blocking rays from said source of radiation and being slanted forward and downward to guide air streams downward on the outside of said front wall.

7. Cooling arrangement as claimed in claim 6 wherein said housing means has a bottom portion having a front end formed with an outlet opening below said front wall for discharging at least a portion of said lower airstream.

8. Cooling arrangement as claimed in claim 1 wherein said transparent roller is located forwardly of said counterpressure roller in the upper portion of said front part of said housing means; and wherein said air outlet means include a plurality of air outlet openings in the upper part of said front part located substantially at the level of said transparent roller so that cooling air streams flow along the top part of said transparent roller.

9. Cooling arrangement as claimed in claim 1 wherein said front part of said housing means includes a front wall having a plurality of slanted wall portions forming between each other horizontal air outlet slots which are at least part of said air outlet means, said slanted wall portions being disposed to block radiation from said source.

10. Cooling arrangement as claimed in claim 9 wherein said slanted wall portions are forwardly and downwardly slanted to block radiation from said source and to guide air streams through said slots downward on the outside of said front wall.

11. Cooling arrangement as claimed in claim 1 wherein said air outlet means in said front part include a plurality of first air outlet openings located in the upper portion of said front part substantially at the level of said transparent roller, and at least one second air outlet opening located in the bottom portion of said front part below the level of said transparent roller so that said air streams flow in said front part forwardly above and below said transparent roller.

References Cited UNITED STATES PATENTS 2,351,339 6/1944 Hruby 355- 2,311,849 2/1943 MacDonald 355-110 2,467,241 4/ 1949 Streich 355-110 2,690,106 9/1954 Trump 355-104 3,329,076 7/1967 Bishop 355-110 3,344,728 10/ 1967 Macquarrie 355-110 SAMUEL S. MATTHEWS, Primary Examiner R. L. MOSES, Assistant Examiner U.S. Cl. X.R. 355-30, 106 

